Power source derating component protection system

TECHNICAL FIELD

0001The present disclosure relates generally to a component protection system and, more particularly, to a component protection system that implements power source derating.

BACKGROUND

0002A work machine may include many different fluid systems having multiple components within each system. Although single component failures within the various systems may not be completely preventable, continued operation of the work machine under component failure conditions could result in complete fluid system failure. Engine protection systems have been implemented that monitor engine fluid conditions and implement routines to protect the engine when the fluid conditions of the engine are not within acceptable ranges.

0003One such protection system is described in U.S. Pat. No. 5,070,832 (the '832 patent) to Hapke et al. The '832 patent teaches an engine protection system that monitors various engine fluid parameters and compares the parameters to limit values. If a fluid fault condition exists, the engine performance is derated to prevent catastrophic failure of the engine.

0004Although the engine protection system of the '832 patent may protect the engine of a work machine when the engine fluid operating conditions exceed acceptable limits, it may do nothing to protect work machine systems that are external to the engine. In particular, because the fluid conditions monitored by the engine protection system of the '832 patent are not related to fluid conditions of work machine systems external to the engine, these external systems may continue to operate to the point of complete system failure after a single component malfunction without detection of a fluid condition abnormality and/or intervention by the engine protection system.

0005The disclosed component protection system is directed to overcoming one or more of the problems set forth above.

SUMMARY OF THE INVENTION

0006In one aspect, the present disclosure is directed to a component protection system for a work machine that has a power source. The component protection system includes at least one sensor configured to monitor a fluid parameter of a work machine system external to the power source and to produce a signal indicative of a value of the fluid parameter. The component protection system also includes a control module in communication with the at least one sensor, the control module being configured to derate a power source output based upon the value of the fluid parameter.

0007In another aspect, the present disclosure is directed to a method of protecting a work machine system external to a work machine power source. The method includes monitoring a fluid parameter associated with the work machine system and derating an output of the work machine power source base upon a value of the fluid parameter.

BRIEF DESCRIPTION OF THE DRAWINGS

0008<figref idref="DRAWINGS">FIG. 1</figref> is a diagrammatic illustration of an exemplary disclosed component protection system; and

0009<figref idref="DRAWINGS">FIG. 2</figref> is an exemplary process flow chart for the component protection system of <figref idref="DRAWINGS">FIG. 1</figref>.

DETAILED DESCRIPTION

0010<figref idref="DRAWINGS">FIG. 1</figref> illustrates an exemplary work machine <b>10</b>. Work machine <b>10</b> may be a fixed or mobile machine that performs some type of operation associated with an industry such as mining, construction, farming, transportation, or any other industry known in the art. For example, work machine <b>10</b> may be an earth moving machine such as a dozer, a loader, an excavator, a motor grader, a dump truck, or any other earth moving machine. Work machine <b>10</b> may alternately be a generator set, a pump, a marine vessel, a passenger vehicle, or any other suitable operation-performing work machine. Work machine <b>10</b> may include a power source <b>12</b>, a transmission <b>14</b>, a hydraulic system <b>16</b>, and a component protection system <b>18</b>.

0011Power source <b>12</b> may include an internal combustion engine such as, for example, a diesel engine, a gasoline engine, a natural gas engine, or any other engine apparent to one skilled in the art. Power source <b>12</b> may, alternately, include another source of power such as a furnace, a battery, a fuel cell, or any other source of power known in the art. In one embodiment, power source <b>12</b> may be a four cylinder diesel engine having one fuel injector <b>20</b> per cylinder. It is contemplated that power source <b>12</b> may have a greater or lesser number of cylinders and/or a different number of fuel injectors <b>20</b> per cylinder.

0012Transmission <b>14</b> may be configured to transmit power from power source <b>12</b> to an output device (not shown) at a range of output speed ratios. Transmission <b>14</b> may be a hydraulic transmission, a mechanical transmission, a hydro-mechanical transmission, or any other suitable transmission. The output device may include such devices as a ground engaging device, a pump, a generator, a propeller, or any other output device known in the art. An input drive member such as, for example, a countershaft <b>22</b>, may connect power source <b>12</b> to transmission <b>14</b>. Transmission <b>14</b> may also include an output driven member such as, for example, an output shaft <b>24</b> connecting transmission <b>14</b> to the output device. In this manner, power generated by power source <b>12</b> may be transmitted through output shaft <b>24</b> to the output device. It is contemplated that transmission <b>14</b> may alternately transmit power from power source <b>12</b> to the output device at only a single output speed ratio.

0013Hydraulic system <b>16</b> may include components configured to hydraulically transfer power from power source <b>12</b> to one or more work tools (not shown) in response to an operator input. Specifically, hydraulic system <b>16</b> may include a pump <b>26</b> configured to pressurize a fluid directed to one or more hydraulic cylinders <b>28</b>.

0014Pump <b>26</b> may be a variable displacement pump, a fixed displacement pump, a variable flow pump, or any other source of pressurized fluid known in the art. Pump <b>26</b> may be drivably connected to power source <b>12</b> via an input drive member such as, for example, a countershaft <b>30</b>. Pump <b>26</b> may convert an input rotation of countershaft <b>30</b> into an output of pressurized fluid. In this manner, mechanical power generated by power source <b>12</b> may be converted to fluid power.

0015Hydraulic cylinder <b>28</b> may be fluidly connected to pump <b>26</b> via a fluid passageway <b>32</b> and may function to actuate the work tool. In particular, hydraulic cylinder <b>28</b> may be supplied with the pressurized fluid from pump <b>26</b> to cause a piston assembly (not shown) within hydraulic cylinder <b>28</b> to displace within a tube (not shown) of hydraulic cylinder <b>28</b>, thereby increasing an effective length of hydraulic cylinder <b>28</b>. Hydraulic cylinder <b>28</b> may also be connected to a fluid drain (not shown) to cause the piston assembly to displace within the tube to decrease the effective length of hydraulic cylinder <b>28</b>. In this manner, the expansion and retraction of hydraulic cylinder <b>28</b> may convert the fluid power from pump <b>26</b> to mechanical power that assists the movement of the work tool. It is contemplated that hydraulic cylinder <b>28</b> may be omitted, if desired, and a different hydraulic device may be fluidly coupled to pump <b>26</b>.

0016Component protection system <b>18</b> may be in communication with transmission <b>14</b>, hydraulic system <b>16</b>, and power source <b>12</b>. Specifically, component protection system <b>18</b> may include a control module <b>34</b> in communication with a transmission sensor <b>36</b> via a communication line <b>38</b>, with a hydraulic system sensor <b>40</b> via a communication line <b>42</b>, and with injectors <b>20</b> of power source <b>12</b> via a communication line <b>44</b>.

0017Control module <b>34</b> may include a microprocessor with a means for storing and comparing information, and for controlling an operation of power source <b>12</b>. Control module <b>34</b> may be embodied in a single microprocessor or multiple microprocessors. Numerous commercially available microprocessors can be configured to perform the functions of control module <b>34</b>. It should be appreciated that control module <b>34</b> could readily be embodied in a general work machine microprocessor capable of controlling numerous work machine functions. Control module <b>34</b> may include any means for storing, comparing, and controlling such as a memory, one or more data storage devices, or any other components that may be used to run an application. Furthermore, although aspects of the present disclosure may be generally described as being stored in memory, one skilled in the art will appreciate that these aspects can be stored on or read from types of computer-related products or computer-readable media such as computer chips and secondary storage devices, including hard disks, floppy disks, optical media, CD-ROM, or other forms of RAM or ROM. Various other known circuits may be associated with control module <b>34</b>, including power supply circuitry, signal-conditioning circuitry, solenoid driver circuitry, communication circuitry, and other appropriate circuitry.

0018Transmission sensor <b>36</b> may be configured to sense a fluid parameter of transmission <b>14</b> and to generate a signal having a value indicative of the fluid parameter. For example, transmission sensor <b>36</b> may be configured to sense a fluid parameter of a fluid provided to a clutch (not shown) within transmission <b>14</b>, to sense a fluid parameter of a fluid within a sump (not shown) of transmission <b>14</b>, to sense a fluid parameter of a fluid directed between a pump (not shown) and a motor (not shown) within transmission <b>14</b>, or to sense a fluid parameter of any other suitable fluid within transmission <b>14</b>. The fluid parameter sensed by transmission sensor <b>36</b> may include, for example, a pressure, a temperature, a viscosity, or any other transmission fluid parameter known in the art.

0019Hydraulic system sensor <b>40</b> may be configured to sense a parameter of the fluid directed between pump <b>26</b> and hydraulic cylinder <b>28</b> within hydraulic system <b>16</b>, to sense a fluid parameter of a fluid within a sump (not shown) of hydraulic system <b>16</b>, or to sense a fluid parameter of any other suitable fluid within hydraulic system <b>16</b>. The fluid parameter sensed by hydraulic system sensor <b>40</b> may include, for example, a pressure, a temperature, a viscosity, or any other hydraulic system fluid parameter known in the art.

0020Control module <b>34</b> may configured to change an operation of power source <b>12</b>. Operational changes of power source <b>12</b> may include derating an output of power source <b>12</b> such as, for example, an output torque and/or an output speed. Derating an output of power source <b>12</b> may include lowering a maximum output of power source <b>12</b> over an entire operating range of power source <b>12</b>. For example, a maximum output torque may be lowered over a range of output speeds by changing fuel delivery characteristics of fuel injectors <b>20</b>. Similarly, a maximum output speed may be lowered over a range of transmission output ratios. The fuel delivery characteristics available for modification may include a fuel delivery amount, a fuel delivery timing, and any other fuel delivery characteristics known in the art.

0021Control module <b>34</b> may change the operation of power source <b>12</b> in response to signals from transmission sensor <b>36</b> and/or hydraulic system sensor <b>40</b>. By means of example, control module <b>34</b> may include a table of derate percent values stored in the memory of control module <b>34</b>. As will be described in more detail in the following section, these derate percent values may be related to values of the signals produced by transmission sensor <b>36</b> and/or hydraulic system sensor <b>40</b>. It is contemplated that the table may be omitted, if desired, and that control module <b>34</b> may alternately derate power source <b>12</b> based upon one or more predetermined equations as functions of the signal values from transmission sensor <b>36</b> and/or hydraulic system sensor <b>40</b>.

0022<figref idref="DRAWINGS">FIG. 2</figref> illustrates a flowchart <b>46</b> depicting an exemplary method for operating component protection system <b>18</b>. Flowchart <b>46</b> will be described in further detail in the following section.

INDUSTRIAL APPLICABILITY

0023The disclosed component protection system finds potential application in any power system where it is desirable to protect components of a work machine auxiliary system that is external to a main power source and driven by the main power source. Specifically, when a sensed fluid parameter value of an auxiliary system is indicative of a component failure within the auxiliary system, an operation of the main power source may be controlled to prevent the power source from driving the auxiliary system to further detriment.

0024Referring to <figref idref="DRAWINGS">FIG. 2</figref>, when component protection system <b>18</b> is in operation, the value of one or more fluid parameters within transmission <b>14</b> and/or hydraulic system <b>16</b> may be continuously sensed and compared with predetermined acceptable ranges for the particular fluid parameters (step <b>100</b>). It is also contemplated that the value of one or more fluid parameters within transmission <b>14</b> and/or hydraulic system <b>16</b> may be checked at predetermined time intervals. Component protection system <b>18</b> may then determine if the values of the fluid parameters are within the predetermined acceptable ranges (step <b>110</b>). If the value of the fluid parameters are within the predetermined acceptable ranges, component protection system <b>18</b> may continue to sense the fluid parameters without changing an output of power source <b>12</b> (step <b>100</b>).

0025However, if one or more of the fluid parameter values deviate from the predetermined acceptable ranges, the magnitude of the deviation may be quantified and compared to the derate table stored in the memory of control module <b>34</b> to determine an appropriate derate percent that will protect transmission <b>14</b> and/or hydraulic system <b>16</b> from further damage (step <b>120</b>). The derate table may include specific derate percent values that correspond with specific parameter values. Appropriate derate percent values, which correspond with parameter values that are not listed in the table, may be determined through, for example, linearly interpolation or extrapolation. It is contemplated that the appropriate derate percents for parameter values not listed in the derate table may, alternately, be non-linearly interpolated or extrapolated according to one or more predetermined equations. It is further contemplated that all appropriate derate percents may be calculated using a desired formula.

0026Once the derate percent value has been determined, this value may be applied to power source <b>12</b> (step <b>130</b>). As described above, the derate may be implemented by controlling a fuel injection quantity and/or fuel injection timing of injectors <b>20</b>. It is contemplated that prior to derating operation of power source <b>12</b>, a warning consisting of, for example, the actuation of a warning lamp and or a warning signal may be initiated when the values of the sensed parameters have exceeded the predetermined acceptable ranges, but have not yet exceeded a minimum derate threshold. During and after derate, control module <b>34</b> may continue to sense the fluid parameters of transmission <b>14</b> and/or hydraulic system <b>16</b> to determine if further action is required (step <b>100</b>).

0027Regardless of the magnitude of deviation beyond the predetermined acceptable range, the maximum amount of derate may be limited to a maximum output under non-derated operation. In one example, the maximum amount of derate may be limited to a maximum derate of 50% of the power source maximum output. In this manner, sufficient power source output may be maintained that ensures safe operation of work machine <b>10</b> and/or that ensures the capability for the work machine <b>10</b> to return to a service bay for repair (“limp-home capacity”).

0028Several advantages are realized because the operation of power source <b>12</b> may be changed in response to a sensed parameter of a fluid system external to power source <b>12</b>. A minor component failure that can be cost-effectively repaired may be quickly brought to the attention of a work machine operator. In addition, automatic reduction of the power source driving force and/or speed that might otherwise contribute to system-wide failure, may result in the failed component have a limited damaging effect on the associated system.

0029It will be apparent to those skilled in the art that various modifications and variations can be made to the component protection system of the present disclosure. Other embodiments of the component protection system will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the invention being indicated by the following claims and their equivalents.